The invention relates to a tube arrangement comprised of at least the following components:
A flexible double-casing tube comprised of an inner tube and an outer tube, forming a ring gap that opens out into a widened intermediate cavity in the vicinity of the ends of the tubes;
a connector that is arranged on each end of the double-casing tube, whereby the connector comprises a flange and a fitting; whereby the fitting in turn comprises in the vicinity of the end zone of the outer tube and the intermediate cavity a first annular bead, as well as mostly within the end zone of the inner tube a second annular bead and, furthermore, is provided with a gap-shaped chamber that is located between the flange and the first annular bead and surrounded by a chamber enclosure; and whereby, furthermore, the chamber is connected with the intermediate cavity, and a drilled hole is provided in the enclosure of the chamber; as well as
a signal transmitter located at each end of the tube in the vicinity of the fitting, whereby each signal transmitter is connected to the drilled hole in the enclosure of the chamber by means of a connector opening.
A tube arrangement of the type specified that comprises a signaling or alarm system that can be activated, is known, for example from published patent documents DE 44 02 255 A1 and EP 0 695 902 B1. The mode of operation is described in said documents only briefly.
In case of any failure of the inner tube, the outer tube absorbs the pressure, so that no medium can leak to the outside. As the outer tube has a higher radial expansion under pressure than the inner tube, a gap is formed between the two tubes when the inner tube fails. The medium penetrates such a gap up into the zone of the fitting. The area of the fitting is realized in such a way that the medium is guided in a controlled manner through channels leading to an opening. Signal transmitters are installed on said opening.
The signal transmitters are mounted on both ends of the tube in the vicinity of the fitting and report any failure of the inner tube. Said signal transmitters may be of the electrical or mechanical type. The electrical signal transmitters have the drawback that the contacts have to be protected against corrosion. This is expensive and requires much expenditure. Furthermore, a central receiving station has to be available and occupied. This requires high expenditure particularly in the area where different operators work in shifts.
Now, excluding the drawbacks specified above, the tube system as defined in the characterizing part of claim 1 is characterized in that the first signal transmitter is an inflatable container, and the second signal transmitter is a lamp with light sticks.
Useful variations of the tube system as defined by the invention are specified in claims 2 to 12.